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ICANN Acronyms and Terms

ICANN has hundreds of acronyms and terms, which can be confusing. We created this multilingual tool to help explain what these terms mean and facilitate your work within the ICANN community. Search for terms by name or acronym using the search bar, or search by letter. All acronyms and terms are available in Arabic, Chinese, French, Russian, and Spanish.

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  • autonomous system numberASN

    A globally unique identifier given to an autonomous system (AS). An AS is a collection of Internet Protocol (IP) networks operated by one or more network operators. When an Internet user sends a message to an IP address that exists outside the user’s own AS, routers forward the message to the AS in which the address resides. In this respect, the Internet uses ASNs to route messages between autonomous systems in much the same way postal systems use postal codes to route physical mail between geographic regions.

    ASNs are allocated to network operators by Regional Internet Registries.